NEOPLASIA Flashcards
occurs when a group of cells becomes free of normal growth control mechanisms, grows without regard for the normal structural
and functional aspects of a tissue or an organ and excessive growth becomes
autonomous
Neoplasia
Neoplasia literally means “____”, and this tissue growth is
called ____
new growth
neoplasm
is an abnormal mass of tissue,
the growth of which exceeds and is uncoordinated with that of normal
tissues, and persists in the same excessive manner even after stoppage of the
stimulus that evoked the change
Neoplasm or a TUMOR
The key features of neoplasia that
distinguishes it from other forms of cell proliferation include the following:
1) Excessive tissue growth
2) Lack of responsiveness to normal control mechanisms
3) Lack of dependence on the continued presence of the stimulus
- means tissue swelling or mass, but by common usage has come
to mean neoplasm.
TUMOR
is a common term used to mean malignant neoplasm
CANCER
is the study of neoplasia, and this word is the basis of
oncogenesis and oncogenic, which relate to the induction of
neoplasia.
ONCOLOGY
The common term for a neoplasm is ________ and both of these tend to be used all-inclusively.
cancer, or tumor,
best considered as a parasitic abnormal mass of cells which grows more or less progressively unless excised or controlled by
therapeutic intervention” (by Robbins in 1927).
Neoplasm
A is an abnormal mass of tissue, the growth of which
exceeds and is uncoordinated with that of the normal tissues and persists in
the same excessive manner after cessation of the stimuli which evoked the
change (Willis 1976).
neoplasm or a tumor
occurs in response to loss of tissue, increased functional
demands, disturbed hormonal activity and immunologic stimulation (i.e.,
lymphoid hyperplasia following active vaccination).
Hyperplasia
DIFFERENCE BETWEEN HYPERPLASIA AND NEOPLASIA
In summary, neoplasia is
uncoordinated proliferation of tissue,
independent of the structural and
functional patterns of normal tissue,
and is indefinitely progressive.
is fundamental and is of primary
importance and can be specified in most instances
Histogenetic - Histogenesis
is secondary and may
become arbitrary and subjective in interpretation
Behavioral (or the clinical course)- behavior
Histogenic – this is based on the tissue origin (Histogenic) as
1.
2.
- Mesenchymal
- Epithelial
Most are of one neoplastic cell type and fit into one or the other of these two
groups. A few types of neoplasm contain more than one neoplastic cell type. When they
are derived from one embryonic germ layer, they are called Mixed Neoplasm
(e.g.mammary tumors in dogs in which proliferating epithelial tissue is intermixed with
mesenchymal components, bone and cartilage)
Let’s break it down:
Definition
Neoplasms (tumors) are abnormal cell growths. Most tumors originate from a single cell type.
Two Main Groups
- Monophasic: Tumors composed of one cell type (e.g., carcinoma, lymphoma).
- Biphasic/Multiphasic: Tumors containing multiple cell types.
Mixed Neoplasms
Tumors with multiple cell types originating from the same embryonic germ layer (ectoderm, endoderm, mesoderm) are called Mixed Neoplasms.
Characteristics
- Derived from one embryonic germ layer.
- Contain multiple neoplastic cell types (e.g., epithelial, mesenchymal).
- Examples:
- Mammary tumors in dogs (epithelial + mesenchymal components).
- Phyllodes tumors (breast).
- Teratomas (germ cell tumors).
Embryonic Germ Layers
- Ectoderm (skin, nervous system).
- Endoderm (internal organs, glands).
- Mesoderm (connective tissue, bone, cartilage).
Examples of Mixed Neoplasms
- Mammary tumors (dogs): Epithelial + mesenchymal (bone, cartilage).
- Teratomas: Multiple tissues (hair, muscle, bone).
- Phyllodes tumors (breast): Epithelial + mesenchymal.
- Fibroadenoma (breast): Epithelial + mesenchymal.
Now, do you have a clearer understanding?
A few types of neoplasm contain more than one neoplastic cell type. When they
are derived from one embryonic germ layer, they are called
Mixed Neoplasm
is a neoplasm containing tissues derived from more than
one germ cell layer, and may contain any number of tissues of any type
including bone, skin, nervous tissue, muscle, hair and other.
TERATOMA
– this is another classificationthat is based on the growth
behavior of neoplastic cells.
Behavioral
- describes those which are relatively inoffensive.
-neoplasms that are confined,
slow-growing and noninvasive
benign neoplasm
which are aggressive and potentially life threatening.
- tumors that are invasive, rapidly
growing and dangerous are called
malignant and carry the suffix sarcoma
if derived from mesenchymal tissue or
the suffix carcinoma if derived from
epithelial tissue.
malignant neoplasm -
“OMA” - a suffix that refers to a BENIGN TUMOR and is used for
neoplasms that are confined, slow growing and noninvasive. Benign tumors
of either mesenchymal or epithelial origin carry the suffix “OMA”
– a suffix used for malignant tumor of epithelial origin.
CARCINOMA
– a suffix for malignant tumor of mesenchymal origin.
SARCOMA
